How to Use “Care of” or C/O in an Address

What does it mean?

Often abbreviated as c/o, “care of” means through someone or by way of someone. This phrase indicates that something is to be delivered to an addressee where they don’t normally receive correspondence. In practice, it lets the post office know the recipient is not the normal recipient at that street address.
 

How is it abbreviated?

c/o

How do I use it?

Write the recipient’s name on the first line, as you do with most letters. Start the second line with “c/o” followed by the person or company name associated with the address you are using.

Examples

Business Example

It can come in handy when trying to get in touch with someone whose home address you don’t know. It can also be useful to call attention to a specific person. In this way it is like including “attention” in your address. This could be useful if you needed to send thank you card.

Bob Smith
c/o ACME Company, Inc.
123 Street St.
City, ST 99999

Hotel Example

You can also use it to send a letter to someone staying at a hotel if you don’t know their room number.

Jane Doe
c/o Westin Hotel
123 Street St.
City, ST 99999

Event Invitation Example

Imagine you are sending invitations to an event and don’t know an invitee’s (John Doe) address. If you know that John and Sarah are friends, you can send an invitation intended for John to Sarah’s address. This only works if you are also inviting Sarah to the event too.

John Doe
c/o Sarah Smith
123 Street St.
City, ST 99999

Is it still used?

Care of is still mentioned in multiple USPS manual entries. Here, in the recipient services manual in section 1.1.8.h, it mentions that restricted delivery packages marked with “Care Of” can be signed by either party.

Google Trends

It’s usage appears to be constant over the last decade with some seasonality in Spring.

Google nGram

I’m not quite sure what would cause a spike between 1916 and 1920. In absolute terms, the spike is pretty small.

Sources

http://www.businessdictionary.com/definition/c-o.html
http://dictionary.cambridge.org/us/dictionary/english/c-o
http://www.dictionary.com/browse/in-care-of
http://www.wikihow.com/Address-an-Envelope-in-Care-of-Someone-Else